1. Field of the Invention
The present invention concerns a single-phase electromagnetic actuator, designed more particularly for applications requiring low-amplitude strokes.
2. Discussion of the Art
Actuators are known in the state of the art that include a first part moving along a direction Y and a second, fixed stator part made of a material with a very high magnetic permeability that contains at least one coil. Such actuators are, for example, claimed in the applicant's French Patent No. 2,648,633. The actuator, according to this embodiment, includes a transversely magnetized thin magnet with the peculiarity of providing a constant force throughout the entire stroke and an absence of magnetostatic force.
Also known from the prior art are actuators described, for example, in European Patent No. 157,632 or U.S. Pat. No. 4,779,582. These actuators contain two electrical coils acting antagonistically on a movable unit containing a thick-walled permanent magnet.
Such devices of the prior art present the disadvantages of the law of nonlinear force in relation to the current injected into the coils, a large amount of occupied space in the radial direction and a low efficiency in force per watt.